====================================================== WARNING: possible circular locking dependency detected 5.10.234 #1 Not tainted ------------------------------------------------------ syz-executor.1/10146 is trying to acquire lock: ffff88800ff24b78 ((work_completion)(&hdev->bg_scan_update)){+.+.}-{0:0}, at: __flush_work+0xdd/0xa90 kernel/workqueue.c:3050 but task is already holding lock: ffffffff8561efe8 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_fop_write+0xff/0x4b0 net/rfkill/core.c:1232 FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: CPU: 1 PID: 10154 Comm: syz-executor.2 Not tainted 5.10.234 #1 -> #4 ( Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 rfkill_global_mutex){+.+.}-{3:3} Call Trace: : __mutex_lock_common kernel/locking/mutex.c:968 [inline] __mutex_lock+0x13d/0x10b0 kernel/locking/mutex.c:1109 __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x107/0x167 lib/dump_stack.c:118 rfkill_register+0x36/0xa10 net/rfkill/core.c:1016 hci_register_dev+0x42e/0xc00 net/bluetooth/hci_core.c:3774 fail_dump lib/fault-inject.c:52 [inline] should_fail.cold+0x5/0xa lib/fault-inject.c:146 __vhci_create_device+0x2c8/0x5c0 drivers/bluetooth/hci_vhci.c:129 vhci_create_device drivers/bluetooth/hci_vhci.c:153 [inline] vhci_open_timeout+0x38/0x50 drivers/bluetooth/hci_vhci.c:310 process_one_work+0x9a9/0x14b0 kernel/workqueue.c:2282 should_failslab+0x5/0x20 mm/slab_common.c:1200 worker_thread+0x61d/0x1310 kernel/workqueue.c:2428 slab_pre_alloc_hook mm/slab.h:515 [inline] slab_alloc_node mm/slub.c:2821 [inline] slab_alloc mm/slub.c:2904 [inline] kmem_cache_alloc+0x5b/0x310 mm/slub.c:2909 kthread+0x38f/0x470 kernel/kthread.c:328 getname_flags.part.0+0x50/0x4f0 fs/namei.c:138 ret_from_fork+0x22/0x30 arch/x86/entry/entry_64.S:298 getname_flags include/linux/audit.h:320 [inline] getname+0x8e/0xd0 fs/namei.c:209 -> #3 do_sys_openat2+0xf9/0x4d0 fs/open.c:1221 (&data->open_mutex ){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:968 [inline] __mutex_lock+0x13d/0x10b0 kernel/locking/mutex.c:1109 vhci_send_frame+0x63/0xa0 drivers/bluetooth/hci_vhci.c:71 do_sys_open fs/open.c:1243 [inline] __do_sys_openat fs/open.c:1259 [inline] __se_sys_openat fs/open.c:1254 [inline] __x64_sys_openat+0x13f/0x1f0 fs/open.c:1254 hci_send_frame+0x1b9/0x320 net/bluetooth/hci_core.c:4065 hci_sched_acl_pkt net/bluetooth/hci_core.c:4590 [inline] hci_sched_acl net/bluetooth/hci_core.c:4675 [inline] hci_tx_work+0xfb4/0x15d0 net/bluetooth/hci_core.c:4741 process_one_work+0x9a9/0x14b0 kernel/workqueue.c:2282 worker_thread+0x61d/0x1310 kernel/workqueue.c:2428 kthread+0x38f/0x470 kernel/kthread.c:328 ret_from_fork+0x22/0x30 arch/x86/entry/entry_64.S:298 -> #2 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 ( entry_SYSCALL_64_after_hwframe+0x67/0xd1 (work_completion)(&hdev->tx_work) RIP: 0033:0x7f7c55d35a04 ){+.+.}-{0:0}: Code: 84 00 00 00 00 00 44 89 54 24 0c e8 96 f9 ff ff 44 8b 54 24 0c 44 89 e2 48 89 ee 41 89 c0 bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 77 34 44 89 c7 89 44 24 0c e8 c8 f9 ff ff 8b 44 __flush_work+0x105/0xa90 kernel/workqueue.c:3053 RSP: 002b:00007f7c532f7ed0 EFLAGS: 00000293 hci_dev_do_close+0x131/0x1240 net/bluetooth/hci_core.c:1745 ORIG_RAX: 0000000000000101 hci_unregister_dev+0x179/0x460 net/bluetooth/hci_core.c:3854 RAX: ffffffffffffffda RBX: 00007f7c55dcc970 RCX: 00007f7c55d35a04 vhci_release+0x70/0xf0 drivers/bluetooth/hci_vhci.c:345 RDX: 0000000000000002 RSI: 00007f7c532f8000 RDI: 00000000ffffff9c __fput+0x285/0x9f0 fs/file_table.c:281 task_work_run+0xe2/0x1a0 kernel/task_work.c:185 RBP: 00007f7c532f8000 R08: 0000000000000000 R09: ffffffffffffffff exit_task_work include/linux/task_work.h:33 [inline] do_exit+0xb6f/0x2600 kernel/exit.c:860 do_group_exit+0x125/0x310 kernel/exit.c:982 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000002 __do_sys_exit_group kernel/exit.c:993 [inline] __se_sys_exit_group kernel/exit.c:991 [inline] __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:991 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 R13: 0000000000000004 R14: 0000000020000580 R15: 0000000000000000 entry_SYSCALL_64_after_hwframe+0x67/0xd1 -> #1 (&hdev->req_lock){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:968 [inline] __mutex_lock+0x13d/0x10b0 kernel/locking/mutex.c:1109 hci_req_sync net/bluetooth/hci_request.c:277 [inline] bg_scan_update+0x82/0x500 net/bluetooth/hci_request.c:2897 process_one_work+0x9a9/0x14b0 kernel/workqueue.c:2282 worker_thread+0x61d/0x1310 kernel/workqueue.c:2428 kthread+0x38f/0x470 kernel/kthread.c:328 ret_from_fork+0x22/0x30 arch/x86/entry/entry_64.S:298 -> #0 ((work_completion)(&hdev->bg_scan_update)){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:2988 [inline] check_prevs_add kernel/locking/lockdep.c:3113 [inline] validate_chain kernel/locking/lockdep.c:3729 [inline] __lock_acquire+0x29e7/0x5b00 kernel/locking/lockdep.c:4955 lock_acquire kernel/locking/lockdep.c:5566 [inline] lock_acquire+0x197/0x470 kernel/locking/lockdep.c:5531 __flush_work+0x105/0xa90 kernel/workqueue.c:3053 __cancel_work_timer+0x368/0x4c0 kernel/workqueue.c:3144 hci_request_cancel_all+0x73/0x230 net/bluetooth/hci_request.c:3440 hci_dev_do_close+0xd9/0x1240 net/bluetooth/hci_core.c:1733 hci_rfkill_set_block+0x166/0x1a0 net/bluetooth/hci_core.c:2223 rfkill_set_block+0x1fd/0x540 net/rfkill/core.c:341 rfkill_fop_write+0x253/0x4b0 net/rfkill/core.c:1240 vfs_write+0x29a/0xb10 fs/read_write.c:603 ksys_write+0x1f6/0x260 fs/read_write.c:658 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x67/0xd1 other info that might help us debug this: Chain exists of: (work_completion)(&hdev->bg_scan_update) --> &data->open_mutex --> rfkill_global_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(rfkill_global_mutex); lock(&data->open_mutex); lock(rfkill_global_mutex); lock((work_completion)(&hdev->bg_scan_update)); *** DEADLOCK *** 1 lock held by syz-executor.1/10146: #0: ffffffff8561efe8 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_fop_write+0xff/0x4b0 net/rfkill/core.c:1232 stack backtrace: CPU: 0 PID: 10146 Comm: syz-executor.1 Not tainted 5.10.234 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x107/0x167 lib/dump_stack.c:118 check_noncircular+0x263/0x2e0 kernel/locking/lockdep.c:2123 check_prev_add kernel/locking/lockdep.c:2988 [inline] check_prevs_add kernel/locking/lockdep.c:3113 [inline] validate_chain kernel/locking/lockdep.c:3729 [inline] __lock_acquire+0x29e7/0x5b00 kernel/locking/lockdep.c:4955 lock_acquire kernel/locking/lockdep.c:5566 [inline] lock_acquire+0x197/0x470 kernel/locking/lockdep.c:5531 __flush_work+0x105/0xa90 kernel/workqueue.c:3053 __cancel_work_timer+0x368/0x4c0 kernel/workqueue.c:3144 hci_request_cancel_all+0x73/0x230 net/bluetooth/hci_request.c:3440 hci_dev_do_close+0xd9/0x1240 net/bluetooth/hci_core.c:1733 hci_rfkill_set_block+0x166/0x1a0 net/bluetooth/hci_core.c:2223 rfkill_set_block+0x1fd/0x540 net/rfkill/core.c:341 rfkill_fop_write+0x253/0x4b0 net/rfkill/core.c:1240 vfs_write+0x29a/0xb10 fs/read_write.c:603 ksys_write+0x1f6/0x260 fs/read_write.c:658 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x67/0xd1 RIP: 0033:0x7fd599887b19 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fd596dfd188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fd59999af60 RCX: 00007fd599887b19 RDX: 0000000000000008 RSI: 0000000020000000 RDI: 0000000000000003 RBP: 00007fd5998e1f6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe54c6b32f R14: 00007fd596dfd300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: 84 00 test %al,(%rax) 2: 00 00 add %al,(%rax) 4: 00 00 add %al,(%rax) 6: 44 89 54 24 0c mov %r10d,0xc(%rsp) b: e8 96 f9 ff ff callq 0xfffff9a6 10: 44 8b 54 24 0c mov 0xc(%rsp),%r10d 15: 44 89 e2 mov %r12d,%edx 18: 48 89 ee mov %rbp,%rsi 1b: 41 89 c0 mov %eax,%r8d 1e: bf 9c ff ff ff mov $0xffffff9c,%edi 23: b8 01 01 00 00 mov $0x101,%eax 28: 0f 05 syscall * 2a: 48 3d 00 f0 ff ff cmp $0xfffffffffffff000,%rax <-- trapping instruction 30: 77 34 ja 0x66 32: 44 89 c7 mov %r8d,%edi 35: 89 44 24 0c mov %eax,0xc(%rsp) 39: e8 c8 f9 ff ff callq 0xfffffa06 3e: 8b .byte 0x8b 3f: 44 rex.R